Application device and corresponding application method

ABSTRACT

The disclosure relates to an application device for applying an application agent (e.g. heat-conducting paste) into a cavity, in particular in a battery module of an electric battery. The application device according to the disclosure comprises a nozzle for dispensing the application agent through the nozzle and a first pressure sensor for measuring a first pressure reading (pA, pB) of the application agent upstream of the nozzle. The disclosure additionally provides a second pressure sensor for measuring a second pressure reading (pD) of the coating agent downstream of the first pressure sensor, in particular in the nozzle. Furthermore, the disclosure comprises a corresponding application method.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage of, and claims priority to, PatentCooperation Treaty Application No. PCT/EP2020/059197, filed on Apr. 1,2020, which application claims priority to German Application No. 102019 109 208.6, filed on Apr. 8, 2019, which applications are herebyincorporated herein by reference in their entireties.

FIELD

The disclosure relates to an application device and a correspondingapplication method for applying an application agent (e.g. adhesive,heat-conducting paste) into a cavity, in particular in a battery moduleof an electric battery.

BACKGROUND

In the production of battery modules for electromobility, one processstep often involves injecting an adhesive or a heat-conducting pasteinto the battery module in order to fill cavities in the battery module.Here, it is important to precisely adhere to the filling volume of theinjected heat-conducting paste. On the one hand, the filling volume ofthe heat-conducting paste must be sufficiently large to ensure that thecavity in the battery module is completely filled with theheat-conducting paste. On the other hand, the filling volume of theheat-conducting paste must not be too large, since overfilling thebattery module can lead to an excessive pressure increase in the batterymodule and, in the worst case, to damage to the battery module due tooverpressure. To set the correct filling volume of the heat-conductingpaste, the volume of the cavity in the battery module has thereforepreviously been measured first. During the application of theheat-conducting paste, the filling volume is then measured by means of avolumetric flow cell, so that the application of the heat-conductingpaste can be terminated when the correct filling volume of theheat-conducting paste has been applied.

However, this known application method has several disadvantages.Firstly, it is always necessary to measure the volume of the cavity inthe battery module before application, which is relativelytime-consuming. Secondly, during the application, a volumetric cell isrequired to measure the filling volume.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A a first embodiment of an application device according to thedisclosure for filling a battery module with a heat-conducting paste,

FIG. 1B a flow chart illustrating the application method of theapplication device according to the disclosure as shown in FIG. 1A,

FIG. 2A a modification of FIG. 1A,

FIG. 2B a modified flow chart explaining the application method of theapplication device according to FIG. 2A,

FIG. 3 a diagram illustrating the gradual reduction of the flow rateduring filling of a battery module,

FIG. 4 a schematic representation of a battery module during filling,

FIG. 5 a modification of FIGS. 1A and 2A, and

FIG. 6 a flow diagram illustrating the detection and localization of afault in the application device.

DETAILED DESCRIPTION

The application device according to the disclosure is preferably usedfor the application of a high-density solid, such as an adhesive or aheat-conducting paste. In principle, however, the application deviceaccording to the disclosure is also suitable for the application ofother application media, such as insulating materials or sealants, toname just a few examples.

Furthermore, the application device according to the disclosure may bedesigned to inject the application agent (e.g. adhesive, heat-conductingpaste) into a cavity of a battery module of an electric battery, inparticular for gap filling in the battery module. However, theapplication device according to the disclosure can in principle also beadapted to fill cavities in other parts or components. In addition, itis also possible in principle for the application device according tothe disclosure to be adapted to coat a component surface with theapplication agent.

In accordance with the known application devices, the application deviceaccording to the disclosure also has a nozzle for dispensing theapplication agent through the nozzle.

Furthermore, in accordance with most known application devices, theapplication device according to the disclosure comprises a firstpressure sensor to measure a first pressure reading of the applicationagent upstream of the nozzle.

The application device according to the disclosure is characterized byan additional second pressure sensor to measure a second pressurereading of the coating agent downstream behind the first pressuresensor, preferably in the nozzle.

Within the scope of the disclosure, at least two pressure readings ofthe coating agent are measured at least two pressure measurement pointswhich are located one behind the other in the direction of flow.

The downstream pressure measuring point is preferably located in thenozzle, so that the second pressure sensor measures the second pressurereading of the coating agent in the nozzle. The upstream pressuremeasuring point, on the other hand, is located upstream of the nozzleand can be located, for example, in a mixer, a metering device or anupstream pump, to name just a few examples.

However, it is alternatively also possible that the downstream pressuremeasuring point is located at a mixer, while the upstream pressuremeasuring point is located at a metering device.

However, the disclosure is not limited to the above examples withrespect to the position of the pressure measuring points.

In one example of the disclosure, the application device comprises atleast a first metering device for conveying the application agent withan adjustable first delivery flow rate (by volume) to the nozzle. Theterm of a metering device used in the context of the disclosure implieshere, according to the usual technical terminology, preferably that thedelivery flow rate of the respective metering device is independent ofthe pressure conditions at the inlet and at the outlet of the meteringdevice.

Furthermore, the application device according to the disclosurepreferably has a control unit. On the input side, the control unit ispreferably connected to the two pressure sensors and thus records thetwo pressure readings measured at the various pressure measuring points.On the output side, on the other hand, the control unit is connected tothe metering device and adjusts the flow rate of the at least onemetering device as a function of the two pressure readings. Furthermore,an additional first pump (e.g. adhesive pump) can preferably beprovided, which delivers the coating agent to the first metering device.

In one example, however, the application agent consists of twocomponents that are mixed together by a mixer. A first metering devicemeters the first component of the application agent with an adjustablefirst volumetric flow rate, while a second metering device meters thesecond component of the application agent with a specific adjustablevolumetric second flow rate. On the output side, the two meteringdevices are connected to the mixer, which mixes the two components ofthe application agent together. Preferably, the mixer is a static mixer,but other mixer types are also possible in principle. On the outputside, the mixer is connected to the nozzle in order to be able to applythe mixed application agent. A pump (e.g. adhesive pump) can beconnected upstream of each of the two metering devices in order toconvey the application agent or the respective component of theapplication agent to the associated metering device.

The aforementioned second pressure reading, which is measured at theupstream pressure measurement point, can be measured, for example, inthe mixer, in a first inlet of the mixer, in a second inlet of the mixeror immediately downstream of the mixer, to name just a few examples.

Thus, within the scope of the disclosure, it is possible for thedownstream pressure reading to be measured in the nozzle while theupstream pressure reading is measured in the upstream mixer.

In contrast, in an example of the disclosure, the upstream pressurereading is measured at the metering device(s). For example, the pressurereading may here be measured in the respective metering device,immediately upstream of the respective metering device, or immediatelydownstream of the respective metering device. The control unit can thenadjust the flow rates of the two metering devices as a function of thethree pressure readings.

In an example of the disclosure, the control unit determines a pressuredifference between the various pressure readings taken at differentpressure measuring points located one behind the other in the directionof flow. The control unit then adjusts the volumetric flow rate of theat least one metering device as a function of this pressure difference.

Thus, the pressure difference between the upstream and downstreampressure readings increases with increasing filling of the cavity. It istherefore useful for the control unit to reduce the flow rate of the atleast one metering device as the pressure difference increases, inparticular in several steps.

Furthermore, within the scope of the disclosure, overfilling of thecavity should be prevented, since such overfilling can lead to damage tothe battery module in extreme cases. Therefore, the control unitpreferably continuously compares the pressure difference with apredetermined maximum value that reflects the pressure load capacity ofthe battery module. The filling of the cavity with the application agentis then terminated by the control unit when the pressure differenceexceeds the maximum value, so that overfilling and pressure overload ofthe battery module are prevented. For example, the control unit can thensimply shut down the metering devices or open a bypass line.

In an example of the disclosure, a total of at least five pressurereadings are measured in the application device, namely at the twometering devices, in the two inlets of the mixer and in the nozzle. Thecontrol unit then adjusts the volumetric flow rates of the two meteringdevices as a function of the five pressure readings. Here, too, apressure difference is preferably formed between upstream pressurereadings on the one hand and downstream pressure readings on the otherhand, with the control unit then setting the delivery flow rates of themetering devices as a function of this pressure difference.

With several pressure sensors located one behind the other in thedirection of flow, it is also possible to detect a fault in theapplication device and localize it within the application device. Forexample, a bursting of a pipe can be detected and localized if thepressure drops immediately behind the defect location. The control unitcan therefore also detect and localize defects in the applicationdevice.

Furthermore, it should also be noted that the term “pressure sensor” asused in the context of the disclosure is to be understood in a generalsense and also includes sensors or measuring arrangements in which atleast one physical quantity other than pressure is measured, thepressure then being derived from the measured physical quantity orquantities.

In the following, a first embodiment of the disclosure is described, asshown in FIG. 1A, whereby the flow chart according to FIG. 1B explainsan application method.

The application device according to the disclosure is used to fillcavities in a battery module 1 with a heat-conducting paste, theheat-conducting paste being injected into the battery module 1 by anozzle 2.

The heat-conducting paste to be applied consists of two components A, B,which are mixed by a static mixer 3 (e.g. grid mixer).

Component A of the heat-conducting paste is conveyed by a pump 4, shownonly schematically, to a metering device 5, which conveys the componentA to the mixer 3 with an adjustable conveying volumetric flow rateQ_(A).

The other component B of the heat-conducting paste, on the other hand,is conveyed by a pump 6 to a further metering device 7, the meteringdevice 7 conveying the component B to the mixer 3 with an adjustableconveying flow rate Q_(B).

The application device has two pressure sensors 8, 9, the pressuresensor 8 measuring a pressure reading p A in the metering device 5,while the pressure sensor 9 measures a pressure reading p_(B) in theother metering device 7.

In addition, the application device has a pressure sensor 10 thatmeasures a pressure reading p_(D) in the nozzle 2.

The pressure sensors 8, 9, 10 are connected to a control unit 11, whichreceives the pressure readings p_(A), p_(B) and p_(D) and sets thedelivery volumetric flow rates Q_(A), Q_(B) of the two metering devices5, 7 as a function of the pressure readings p_(A), p_(B) and p_(D).Here, the control unit 11 ensures that a certain mixing ratio of the twocomponents A, B is maintained.

In the following, the operating method of the application deviceaccording to FIG. 1A is described by means of the flow chart accordingto FIG. 1B.

In a first step S1, the metering device 5 meters the component A of theheat-conducting paste with a certain flow rate Q_(A).

In a simultaneously running step S2, the other metering device 7 meterscomponent B of the heat-conducting paste with the adjustable flow rateQ_(B).

In a simultaneously running step S3, the mixer 3 mixes the twocomponents A and B to form the heat-conducting paste.

In a simultaneous step S4, the heat-conducting paste is injected intothe battery module 1 by the nozzle 2.

In step S5, the pressure readings p_(A), p_(B) and p_(D) are measuredcontinuously.

In a simultaneously running step S6, a pressure difference Δp is thencontinuously measured according to the following formula:

Δp=f(p _(A) ,p _(B))−p _(D).

The pressure difference Δp then represents the pressure differencebetween the downstream pressure measuring point and the upstreampressure measuring point.

It should be mentioned here that the pressure difference Δp increaseswith increasing filling level of the battery module due to the backpressure created. In a step S7 it is therefore continuously checkedwhether the pressure difference Δp exceeds a maximum permissiblepressure value p_(max), where the maximum value p_(max) represents themaximum pressure load capacity of the battery module 1.

If such an excessively high pressure increase is detected, the fillingprocess is terminated in a step S10.

Otherwise, however, in a step S8 it is checked whether the determinedpressure difference Δp exceeds predetermined limit values p_(Limit1),p_(Limit2), p_(Limit3), as shown in FIG. 3 . If these limit values areexceeded, a stepwise reduction of the flow rates Q_(A), Q_(B) then takesplace in a step S9, as can also be seen in FIG. 3 .

The embodiment according to FIGS. 2A and 2B largely coincides with theembodiment described above and illustrated in FIGS. 1A and 1B, so thatto avoid repetition reference is made to the above description, the samereference signs being used for corresponding details.

A special feature of this embodiment is that the pressure sensor 10 formeasuring pressure in the nozzle 2 has been replaced by a pressuresensor 12 for measuring pressure in the mixer 3.

Here, too, however, a pressure difference Δp is measured between theupstream pressure reading p_(M) and another pressure reading derivedfrom the upstream pressure readings p_(A) and p_(B).

FIG. 4 shows in schematic form the battery module 1 with the nozzle 2and the pressure sensor 10, which measures the pressure reading pp inthe nozzle 2. In addition, another pressure sensor 13 is shown, whichmeasures a pressure reading upstream of the pressure sensor 10 and thusalso upstream of the nozzle 2. For example, the pressure sensor 13 canmeasure the pressure reading in the mixer 3, in the metering device 5,in the metering device 7, or elsewhere within the application device.

FIG. 5 shows a modification of FIGS. 1A and 2A, so that to avoidrepetition, reference is made to the above description, with the samereference signs being used for corresponding individual items.

A special feature compared to the embodiment according to FIG. 1A isthat two additional pressure sensors 14, 15 are provided. The pressuresensor 14 measures a pressure reading p_(MA) in the first inlet of themixer 3, while the pressure sensor 15 measures a pressure reading p_(MB)in the second inlet of the mixer 3. As a result, five pressure readingsp_(A), p_(B), p_(MA), p_(MB), p_(D) are measured and evaluated by thecontrol unit 11.

In this way, it is also possible to detect and locate faults in theapplication device, as described below with reference to the flow chartin FIG. 6 .

Thus, in steps S1-S5, the pressure readings p_(A), p_(B), p_(MA), p_(MB)and p_(D) are measured.

In a step S6, a plausibility check is then performed between thesepressure readings, which must be in a certain relationship to each otherfor proper operation.

If the check in a step S7 shows that the pressure readings are plausiblewith respect to each other, normal operation continues.

Otherwise, on the other hand, in a step S8, the error is localizedwithin the application device, namely in relation to the individualpressure measuring points.

In a step S9, a corresponding error signal can then also be generated.

The disclosure is not limited to the preferred embodiments describedabove. Rather, a large number of variants and modifications are possiblewhich also make use of the disclosure.

1.-18. (canceled)
 19. Application method for applying an applicationagent, with the following steps: a) Application of the application agentthrough a nozzle into the cavity, b) measuring a first pressure readingof the application agent by means of a first pressure sensor upstream ofthe nozzle, c) measuring a second pressure reading of the applicationagent by means of a second pressure sensor downstream of the firstpressure sensor. d) metering the application agent with a first deliveryflow rate to the nozzle by means of a first metering device, and e)adjusting the first delivery flow rate of the first metering device as afunction of the two pressure readings.
 20. Application method accordingto claim 19, further comprising the following steps: a) Metering a firstcomponent of the application agent with a first delivery flow rate bymeans of the first metering device, b) metering a second component ofthe application agent with a second delivery flow rate by means of asecond metering device, and c) mixing the two components by means of amixer.
 21. Application method according to claim 20, further comprisingthe following steps: Measuring the second pressure reading at the mixer.22. Application method according to claim 21, wherein the secondpressure reading is measured in the mixer.
 23. Application methodaccording to claim 21, wherein the second pressure reading is measuredin a first inlet of the mixer.
 24. Application method according to claim21, wherein the second pressure reading is measured in a second inlet ofthe mixer.
 25. Application method according to claim 21, wherein thesecond pressure reading is measured immediately downstream of the mixer.26. Application method according to claim 20, further comprising thefollowing steps: a) Measuring the first pressure reading at the firstmetering device by means of the first pressure sensor, b) measuring athird pressure reading at the second metering device by means of a thirdpressure sensor, and c) adjusting the delivery flow rates of themetering devices as a function of the three pressure readings. 27.Application method according to claim 19, further comprising thefollowing steps: a) Determining a pressure difference between thefollowing pressure readings: a1) the second pressure reading measureddownstream on the one hand and a2) a pressure reading measured upstreamon the other hand, and b) setting the delivery flow rate of the at leastone metering device as a function of the determined pressure difference.28. Application method according to claim 27, further comprising thefollowing step: Reducing the delivery flow rate of the at least onemetering device with increasing pressure difference.
 29. Applicationmethod according to claim 27, further comprising the following step:comparing the pressure difference with a predetermined maximum value andstopping the filling of the cavity if the pressure difference exceedsthe maximum value in order to prevent overfilling and pressure overloadof the cavity.
 30. Application method according to claim 19, furthercomprising the following steps: Measuring a plurality of pressurereadings of the coating agent at different measurement points within theapplication device, the measurement points being located one behind theother in the direction of flow.
 31. Application method according toclaim 30, further comprising the following steps: Determination of afault of the application device by an evaluation of the pressurereadings.
 32. Application method according to claim 31, furthercomprising the following step: determination of a position of the faultrelative to the measurement points by an evaluation of the pressurereadings.
 33. Application method according to claim 30, furthercomprising the following steps: a) Comparing a downstream pressurereading with an upstream pressure reading and performing a plausibilitycheck between the pressure readings, and b) generating an error signalif the plausibility check shows that the downstream pressure readingdoes not match the upstream pressure reading.